There are two typical forms for conventional vehicle door sealing device, as shown in FIGS. 1 and 2. In the sealing device disposed between a vehicle door and a vehicle body as shown in FIG. 1, a sealing rubber strip is constituted of a keel rubber portion with a framework inside and a rubber foaming body portion, and the keel rubber strip provided with a groove is installed over a joined edge (also referred to as a front edge in the past) of a steel plate of the vehicle body. In the sealing device disposed between a vehicle door and a vehicle body as shown in FIG. 2, a sealing rubber strip is a rubber foaming body and is connected to a steel plate of the vehicle door with a connecting buckle. Common features between the two devices lie in that a connection surface engaged with the sealing rubber strip is flat such that the rubber strip may be fixed on the flat surface; and a portion with which the rubber foaming body is hermetically engaged is also a flat surface, so that when closing the door, only a radial force is applied to the rubber foaming body of the sealing rubber strip, and is oriented toward a rubber strip mounting base, which will not cause a lateral displacement of the rubber strip relative to the mounting base.
Sealing devices disposed between the vehicle door and the vehicle body in the two structures described above are both applicable to the vehicle body and the vehicle door which are sheet metal parts, but not applicable to the hermetical engagement between a vehicle door and a vehicle body in which the vehicle body doorframe and the vehicle door are both made by bending circular pipes. Since the doorframe and a framework of the door are both have round surfaces, when closing the door, the rubber strip is not only subject to a component force normal to a round cross section of the rubber strip, but also subject to a component force tangent to the round cross section of the rubber strip. Thus, the mounting fixed portion of the rubber strip is likely displaced under the tangential component force. Besides, a vehicle door draining structure of the sealing device disposed between the vehicle door and the vehicle body is shown in FIG. 3. A drain opening is provided at the lowest point A inside the vehicle door and is outside of and below the sealing area, such that the vehicle door sealing rubber strip will not affect draining of the vehicle door. Such structure of the sealing device disposed between the vehicle door and the vehicle body also cannot solve the problem of draining the water accumulated inside the vehicle door which is formed by bending circular pipes.